Dead Pixel Test

Why Solid Colors Reveal What You Can't See Normally

During everyday use, your eyes glide over millions of pixels and never notice a single faulty one — a busy desktop, a web page, or a video hides defects in the noise. A dead pixel test strips that noise away by filling the entire screen with one solid color at a time. Against a perfectly uniform field, a single misbehaving pixel becomes obvious: it is the one dot that refuses to match its neighbors.

This test cycles through six full-screen colors — red, green, blue, white, black, and grey — and each one is chosen to expose a different kind of fault. Click, tap, or press the arrow keys to move between colors, and press Esc (or the Exit button) to leave fullscreen at any time.

What Each Color Checks For

Every color in the cycle has a job:

• White — the best background for spotting dead pixels. A dead pixel gets no power and stays black, so it stands out as a permanent dark dot on a bright field.
• Black — the best background for spotting stuck pixels. A stuck pixel is frozen "on," glowing red, green, or blue against the darkness.
• Pure red, green, and blue — isolate individual sub-pixels. Every pixel is made of one red, one green, and one blue sub-pixel; a fault in just one sub-pixel may only appear on its matching color.
• Grey — reveals uniformity issues, backlight bleed, and faint clouding that pure colors can mask.

How to Tell Dead from Stuck

The distinction matters because it predicts whether a fix is possible:

• A dead pixel is always black on every background and never changes. It is electrically dead and almost never recovers.
• A stuck pixel is locked to one color and is brightest against black. Because it still receives power, it can sometimes be coaxed back to normal by rapidly flashing colors, which this test lets you do by cycling quickly.

If a dot appears only on one specific color and disappears on others, you are looking at a single stuck sub-pixel — the most common and most fixable defect.

Interpreting Your Results

Found a defect? Here is how to read it:

• One isolated dot, fixed in place — a genuine dead or stuck pixel. Note its exact position and which colors reveal it.
• A cluster of dots in one area — possible panel damage or a manufacturing defect worth a warranty claim.
• A faint cloudy patch on grey or white — backlight bleed or clouding, not a pixel fault, but still a quality issue on premium displays.

Most manufacturers allow a handful of dead sub-pixels before a panel qualifies for replacement, so check your warranty's pixel policy before deciding whether to return it.

Troubleshooting Tips

• Clean the screen first. A speck of dust or a smudge looks identical to a dead pixel. Wipe the panel with a soft microfiber cloth before you trust a result.
• Press gently to confirm. If a dark spot moves, smears, or spreads under light pressure, it is dirt or physical damage — not a dead pixel, which stays perfectly fixed.
• Try in a dark room. Ambient glare and reflections hide subtle stuck pixels; dimming the lights makes the black-background pass far more reliable.
• Revive stuck pixels. Leave the test cycling rapidly over the faulty spot for several minutes, or gently massage the area through a soft cloth — patience occasionally pays off.

A clean panel is only half of a healthy setup. Once your display passes, check how it actually performs by measuring your reaction time test and putting your hardware through an aim trainer to make sure input and display are working together.